Research On Key Technologies Of Variable Speed Permanent Magnet Synchronous Generator

Variable speed permanent magnet synchronous generator PWM rectifier has some advantages,such as low harmonics of generator current,adjustable power factor,small fluctuations of dc voltage,two-way flow energy,etc,can be widely used in many fields,including of special vehicle power supply,ship power supply,mixed power vehicles,new energy power generation,etc.Therefore,there has important significance that researching the control technology of variable speed permanent magnet synchronous generator system.This paper take ariable speed permanent magnet synchronous generator system as the research object,and combin the research method of theoretical analysis,software simulation and experiment verification,do the research about control technology of ariable speed permanent magnet synchronous generator system under the control of PWM rectifier.Firstly,the application field and the research status under the control of the converter of the variable speed permanent magnet synchronous power generation system have been introduced.The basic structure of the variable speed permanent magnet synchronous power generation system and the working principle for the generator and the converter have been introduced,and the mathematical model of the permanent magnet synchronous generator and the PWM rectifier have been established.The operate features of variable speed permanent magnet synchronous generator Operation under the control of converter have been reseached.Secondly,the conventional vector control strategy of the converter have been studied.Based on the characteristics of the three control strategies,a compound control strategy for variable speed permanent magnet synchronous power generation system have been proposed,so the permanent magnet synchronous generator can be applied in various operating conditions with different load and speed,and the operate efficienc can be improved.Based on the above analysis,a speed sensorless control method based on the estimated current model have been proposed.By this method the estimated current value can be calculate by the equivalent motor model which established by the known parameters.The error between the detected actual current value and the estimated current value is used to revise the the estimated current value,and then the rotor position is obtained by integrating estimated current value.This method is very stable at high speed and strong load capacity at low speed running,which greatly expands the operating range of permanent magnet synchronous generator.The simulation model of conventional vector control,compound control and speed sensorless control system have been established in Matlab/Simulink simulation.The simulation results are in agreement with the theoretical analysis,which verifies the correctness of the method.Finally,the experimental platform of 840kW permanent magnet synchronous generator rectifier have been designed,and some hardware circuits and control software have also been designed.The control strategy of PWM rectifier proposed in this paper is verified by experiments.The experimental results verify the correctness and validity of relevant theoretical analysis and the correctness about proposed design method.